In many parts of the world, recycling is becoming commonplace and even required by law. In recent years, plastic bottles and containers were discarded while glass containers often were recycled or reused. However, even now some regulations in various areas even require plastic containers, such as refillable PET containers, to be recycled or reused.
Many of these PET and similar plastic containers are labeled using a wrap-around labeling process where a leading edge of a label is applied onto the container and secured thereon typically by an adhesive that has been applied onto the leading edge while the label moves with rotating label drum. The container also rotates and draws a label from the label drum. As the container rotates, the label is wrapped about the container and the trailing edge secured by an adhesive either onto the container or overlying the leading edge. If the container has a contoured surface, such as a convex or sloped end portion, a heat shrinkable layer is heat shrunk over the contoured or inclined surface.
When the containers are recycled or reused, the label is stripped from the container. Because the leading edge of the label had been secured by an adhesive onto the container, after the label has been stripped from the container, often a residue of adhesive from the leading edge is retained on the container. This is an undesirable byproduct of that labeling operation.
It would be advantageous if many containers could be labeled and applied by a wrap-around labeling technique without having an adhesive applied onto the leading edge. Additionally, such method and apparatus would be advantageous because it would increase production. Often, a misfed label can create a production "glitch" because an adhesive roller or other means that is used for applying adhesive onto the leading edge of the label would apply adhesive to the surface of the label drum. If this occurs, then an operator often must clean the labeling drum, taking valuable production time and creating greater production costs.
The copending 08/745,820 application discloses and claims a method and apparatus that solves the above-identified problems. A label can be applied onto the container by a wrap around labeling without applying an adhesive onto the leading edge of the label. Labels are held on a label drum and moved into a label applying position as the label drum is rotated. At the same time, a container to be labeled is fed from a feeding mechanism into the labeling applying position. Air is blown from the label drum onto the leading edge of the label at an angle to the label drum surface and in a direction backward along the label from the leading edge to force the leading edge of the label against the container.
As the container rotates, the label leading edge is maintained against the container. The Ser. No. 08/745,820 application further discloses that the leading edge can be maintained by wet adhesion. In another aspect, air also can be blown onto the label and container from the side opposite the label drum to maintain the leading edge of the label against the container while rotating the container so that the label is wrapped about the container. The trailing edge is then secured to the leading edge by an adhesive applied onto the trailing edge.
The 08/845,820 application also discloses a stationary roll-on pad spaced from the label drum that engages the container so that the container is rotated between the label drum and the stationary roll-on pad. Air can then be blown from the roll-on pad onto the label as the leading edge of the label moves into a position adjacent the roll-on pad. The laminar flow of air under the label can be minimized by blowing air from the roll-on pad in both the straight and inclined direction from orifices positioned in the roll-on pad. It is important to reduce the laminar flow of air under the label. Any laminar flow of air under the label creates a Bernoulli Effect, which makes a low pressure under the label, sucking the label tighter against the vacuum drum. Additionally, the laminar flow of air under the label can be minimized by blowing the air from the roll-on pad over a slot formed in the roll-on pad.
Additionally, any laminar flow of air under the label can be minimized as it is blown from the label drum by blowing the air over a slot formed in the label drum.
The label drum can use a solenoid or manifold system to first draw a vacuum on the label as it moves into a label applying position to maintain the label on the drum. After the leading edge has moved into the label applying position, the vacuum is terminated and the leading edge is blown outward by air forced through orifices formed on the surface of the label drum.
The adhesive can be applied onto the trailing edge of the label or applied on a portion of the label extending from the trailing edge and across the label to the medial portion of the label or even to an area adjacent the leading edge of the label. Additionally, if the article has a contoured surface, the container can be moved into a heat shrink oven which shrinks a heat shrinkable label onto the contoured section of the container.